Sloane Stephens defeated U.S. Open Champion Naomi Osaka at the WTA Finals on Monday.

Osaka, who represents Japan, lost 7-5, 4-6, 6-1 to the American Stephens, according to ESPN. This was the first time both women competed at WTA, which was held in Kallang, Singapore.

Osaka admits she struggled during the match.

"That was something I'm not really proud of. I feel like I play better when no one knows what I'm thinking," she said, according to The National.

The 21-year-old still has a chance to make it to the semi-finals if she is able to win at least one match against Angelique Kerber and Kiki Bertens. Osaka is thankful for that opportunity.

"Yeah, I think it's really cool that you can keep going even after you lose. I think that this tournament is really special in that way, because there is no other tournament during the year that does a round-robin format," she said.

"So I think that the fact that you get another chance to learn from your mistakes and apply it in the matches going on is something that's really good."

Stephens admits going against Osaka was a bit intimidating, but says she wasn’t deterred, reports Yahoo.

"I thought I played a really good match. I played solid from start to finish. Obviously playing someone with a lot of confidence is always a tough task, but I think that I played well and I kept a good attitude. So I was pleased with that,” she said after the game.

Osaka recently complained about exhaustion following her 2018 US Open win. Stephens won the competition in 2017 so she knows the feeling.

"Yeah, I mean, I can definitely relate. After the U.S. Open I probably shouldn't have played the entire rest of the season, because I was so exhausted," the 25-year-old said.

"I think our situations are a little different. I played like four tournaments after not having played for 11 months, so I was probably more tired than she was. But I think I totally understand, and I think that to go play at home in Tokyo was really important for her or her fans, for her country. You can only applaud that," Stephens added.

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WTA Finals

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